An information processing system such as a parallel computer system includes a plurality of information processing apparatuses which are connected through a plurality of lanes which are data transmission paths. Further, the information processing apparatus is provided with an expansion slot intended to be connected to peripheral devices such as an input and output device, and an arithmetic processing unit in the information processing apparatus transmits data through a plurality of lanes which are connected to the expansion slot. Further, a method has been proposed in which in this type of information processing apparatus, the lane connected to the expansion slot can be replaced, and degradation of a lane is restored by replacing the degraded lane with a non-used lane, when degradation occurs in a lane in use due to a failure (for example, see Japanese Laid-open Patent Publication No. 2013-200616). Further, a method has been proposed in which in communication devices which are connected with each other through a plurality of physical lanes, a certain logic lane number can be assigned to each physical lane, and thus the communication devices can be connected while avoiding a failed physical lane (for example, see Japanese Laid-open Patent Publication No. 2005-182485).
However, in a case of degrading a normal lane in which a failure does not occur and thereafter, of restoring the degraded lane, if a failure due to a certain cause occurs in the lane being restored, a communication error occurs by restoring the failed lane, and a link between communication devices is disconnected. Therefore, in a case of restoring the degraded lane, when a failure occurs in a lane for which use has been stopped by the degradation, even if the restoration of the lane is instructed, it is preferable to maintain the degradation state without restoring the lane.
In an aspect, an object is to provide an information processing apparatus, an information processing system, and a communication device in which in a case of restoring a degraded lane, when a failure occurs in a lane for which use has been stopped by the degradation, even if the restoration of the lane is instructed, the degradation state of the lane is maintained and thus disconnection in communication between information processing apparatuses is suppressed.